JP2011243438A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device capable of reducing current consumption compared with a prior art.SOLUTION: The display device 1 is provided with a display panel 2 having a display surface A2 display an image and a rear face B2 facing the display surface A2, a backlight unit 3 irradiating a first light La toward the rear face B2 of the display panel 2 and irradiating a second light Lb toward a different direction from the rear face B2, and a photoelectric conversion unit 4 having a first light-receiving surface A4 receiving the second light Lb and a second light-receiving surface B4 receiving a third light Lc from outside, generating a first current Ib by carrying out photoelectric conversion of the second light Lb received by the first light-receiving surface A4, and generating a second current Ic by carrying out photoelectric conversion of the third light Lc received by the second light-receiving surface B4.

Description

  The present invention relates to a display device including a backlight unit.

  At present, as one form of display device, a liquid crystal display device including a backlight unit that irradiates light toward the back surface of the liquid crystal display panel is widely used. A cold cathode tube is generally used as a light source of a backlight unit used in a liquid crystal display device.

The liquid crystal display device displays a predetermined image by driving the liquid crystal filled in the liquid crystal display panel for each pixel in a state where light is irradiated from the backlight unit toward the back of the liquid crystal display panel. is there.
However, in a liquid crystal display device using a cold cathode tube backlight unit, even when the entire screen is black, light is constantly radiated from the backlight unit toward the back of the liquid crystal display panel, which increases current consumption. It is a factor. In particular, a portable liquid crystal display device using a battery has a strong demand for reduction in current consumption because of a short driving time.

Accordingly, liquid crystal display devices using LEDs (Light Emitting Diodes) instead of cold cathode tubes are beginning to appear on the market. In a liquid crystal display device using an LED backlight unit, so-called area control can be performed in which the LED is turned off for each area in accordance with a displayed image, so that the current is larger than that of a liquid crystal display device using a cold cathode tube backlight unit. Consumption can be reduced.
An example of a liquid crystal display device using an LED backlight unit is disclosed in Patent Document 1, for example.

JP 2009-222030 A

  However, at present, the battery capacity is insufficient with respect to the increase in current consumption due to the increase in screen size, and further improvement in current consumption is desired in terms of ecology.

  In view of the above, an object of the present invention is to provide a display device that can reduce current consumption as compared with the related art.

In order to solve the above problems, the present invention provides the following display device.
1) A display panel (2) having a display surface (A2) for displaying an image and a back surface (B2) facing the display surface, and irradiating the first light (La) toward the back surface of the display panel And a backlight unit (3) for irradiating the second light (Lb) in a direction different from the back surface, a first light receiving surface (A4, A54) for receiving the second light, and an external To the second light receiving surface (B4, B54) for receiving the third light (Lc), and photoelectrically converting the second light received by the first light receiving surface to generate a first current (Ib , Ih) and a photoelectric conversion unit (4, 54) for generating a second current (Ic, Ii) by photoelectrically converting the third light received by the second light receiving surface. A display device (1, 50) characterized by comprising:
2) The photoelectric conversion unit (4) includes a first light-receiving surface facing the one light-receiving surface of the first light-receiving surface (A4) and the second light-receiving surface (B4), and the first light-receiving surface. A transparent substrate (21) having an opposing surface, a first transparent electrode (22), which is sequentially formed on the first opposing surface of the transparent substrate, a first hole extraction layer (23), A first electron donor layer (24), a first electron acceptor layer (25), a common reflective electrode (16) reflecting the second light and the third light, and a second electron An acceptor layer (15), a second electron donor layer (14), a second hole extraction layer (13), a second transparent electrode (12), a sealing layer (11), The display device (1) according to 1), comprising:
3) The first electron donor layer, the second electron donor layer, the first electron acceptor layer, and the second electron acceptor layer have a wavelength range of the second light and the second electron acceptor layer, 2. The display device according to 2), wherein each of the display devices includes a first dye having an absorption wavelength region that at least partially overlaps the wavelength region of the third light.
4) The first electron donor layer, the second electron donor layer, the first electron acceptor layer, or the second electron acceptor layer includes a wavelength region of the second light and the second electron acceptor layer. It further includes a second dye having an absorption wavelength region that at least partially overlaps the third light wavelength region, and an emission wavelength region that at least partially overlaps the absorption wavelength region of the first dye. 3. The display device according to 3).
5) The photoelectric conversion unit (54) includes a first light-receiving surface that faces one of the first light-receiving surface (A54) and the second light-receiving surface (B54), and the first light-receiving surface. A transparent substrate (21) having an opposing surface, a transparent electrode (22), a hole extraction layer (13), and an electron donor layer (14) sequentially formed on the first opposing surface of the transparent substrate. ), An electron acceptor layer (15), a transflective electrode (52) that transmits part of the second light and the third light, respectively, and reflects the rest, and a sealing layer ( 11) and the display device (50) according to 1).
6) Each of the electron donor layer and the electron acceptor layer includes a third dye having an absorption wavelength region that at least partially overlaps the wavelength region of the second light and the wavelength region of the third light, respectively. 5. The display device according to 5), comprising:
7) The electron donor layer or the electron acceptor layer has an absorption wavelength region that at least partially overlaps the wavelength region of the second light and the wavelength region of the third light, respectively, The display device according to 6), further comprising a fourth dye having an emission wavelength region at least partially overlapping the absorption wavelength region of the dye.

  According to the present invention, there is an effect that current consumption can be reduced as compared with the prior art.

It is typical sectional drawing for demonstrating Example 1 of the display apparatus of this invention. It is a figure which shows the typical example of the emission spectrum of a cold cathode tube. It is a figure which shows the typical example of the emission spectrum of LED. It is a figure which shows the representative example of the emission spectrum of an organic EL element. 3 is a schematic cross-sectional view for explaining a photoelectric conversion unit of the display device of Example 1. FIG. It is a figure which shows the typical example of the absorption spectrum of fullerene. It is a figure which shows the representative example of the absorption spectrum of zinc phthalocyanine. It is typical sectional drawing for demonstrating Example 2 of the display apparatus of this invention. 6 is a schematic cross-sectional view for explaining a photoelectric conversion unit of a display device of Example 2. FIG. It is a figure which shows the representative example of the absorption spectrum and emission spectrum of rubrene. It is typical sectional drawing for demonstrating Example 3 of the display apparatus of this invention. 6 is a schematic cross-sectional view for explaining a photoelectric conversion unit of a display device of Example 3. FIG. It is a figure which shows the representative example of the absorption spectrum and emission spectrum of coumarin. It is typical sectional drawing for demonstrating Example 4 of the display apparatus of this invention. FIG. 6 is a schematic cross-sectional view for explaining a photoelectric conversion unit of a display device of Example 4. It is typical sectional drawing for demonstrating Example 5 of the display apparatus of this invention. FIG. 10 is a schematic cross-sectional view for explaining a photoelectric conversion unit of a display device of Example 5. It is typical sectional drawing for demonstrating Example 6 of the display apparatus of this invention. FIG. 10 is a schematic cross-sectional view for explaining a photoelectric conversion unit of a display device of Example 6.

  The preferred embodiments of the present invention will be described with reference to FIGS.

<Example 1>
As shown in FIG. 1, the display device 1 includes a transmissive liquid crystal display panel 2 having a display surface A2 and a back surface B2 facing each other, and a light emitting surface A3 and a light emitting surface B3 facing each other, from the light emitting surface A3. For example, a double-sided backlight unit 3 that emits white light La toward the back surface B2 of the liquid crystal display panel 2 and irradiates, for example, white light Lb from a light emitting surface B3 toward a light receiving surface A4 of a photoelectric conversion unit 4 described later. And a light receiving surface A4 for receiving the white light Lb emitted from the light emitting surface B3 of the double-sided backlight unit 3, and a light receiving surface B4 for receiving external light emitted from the outside, for example, sunlight Lc. The photoelectric conversion unit 4 that photoelectrically converts the white light Lb received by the light receiving surface A4 to generate the current Ib and photoelectrically converts the sunlight Lc received by the light receiving surface B4 to generate the current Ic; A current reservoir 5 such as a battery for storing current Ib and the current Ic generated by the unit 4, and a.

  White light La emitted from the light emitting surface A3 of the backlight unit 3 to the back surface B2 of the liquid crystal display panel 2 is modulated for each pixel by the liquid crystal display panel 2 and displayed as an image on the display surface A2 of the liquid crystal display panel 2. .

  As the light source of the backlight unit 3, for example, a cold cathode tube, an LED (Light Emitting Diode), and an organic EL (Electro-Luminescence) element can be used.

Here, emission spectra of the cold cathode fluorescent lamp, the LED, and the organic EL element will be described with reference to FIGS.
FIG. 2 shows a typical example of the emission spectrum of a cold cathode tube. FIG. 3 shows a typical example of the emission spectrum of the LED. FIG. 4 shows a representative example of the emission spectrum of the organic EL element. 2 to 4, the horizontal axis indicates the emission wavelength, and the vertical axis indicates the emission intensity.

  As shown in FIG. 2, the emission spectrum of the cold-cathode tube has strong emission peaks at emission wavelengths of around 430 nm, 550 nm, and 610 nm, all of which are steep peaks with a narrow half-value width. Therefore, the amount of current Ib generated by the photoelectric conversion unit 10 is small.

  On the other hand, as shown in FIG. 3, the emission spectrum of the LED has a strong emission intensity peak near the emission wavelength of around 460 nm and around 560 nm, and both peaks are broad peaks with a wide half-value width. The amount of current Ib generated by the photoelectric conversion unit 10 is larger than when a cold cathode tube is used.

  As shown in FIG. 4, the emission spectrum of the organic EL element has a peak with a strong emission intensity in the vicinity of 460 nm and 560 nm, almost the same as the emission spectrum of the LED. Therefore, the amount of current Ib generated by the photoelectric conversion unit 10 is larger than when a cold cathode tube is used.

For the reasons described above, it is preferable to use an LED or an organic EL element as a light source of the backlight unit 3 rather than a cold cathode tube.
Also, by using an LED or organic EL element as the light source of the backlight unit 3, so-called area control can be performed in which the LED or organic EL element is turned off or the illuminance is adjusted for each area according to the displayed image. Current consumption can be reduced as compared with the case of using a cathode tube.

  As shown in FIG. 5, the photoelectric conversion unit 4 is a photoelectric conversion unit that photoelectrically converts the white light Lb irradiated from the light emitting surface B3 (see FIG. 1) of the backlight unit 3 to the light receiving surface A4 to generate a current Ib. 10 and a photoelectric conversion unit 20 that photoelectrically converts sunlight Lc irradiated on the light receiving surface B4 from the outside to generate a current Ic.

  The photoelectric conversion unit 10 is arranged in the order of the sealing layer 11, the transparent electrode 12, the hole extraction layer 13, the electron donor layer 14, the electron acceptor layer 15, and the common reflective electrode 16 from the backlight unit 3 side. It has a laminated structure.

  The photoelectric conversion unit 20 is arranged in the order of the transparent substrate 21, the transparent electrode 22, the hole extraction layer 23, the electron donor layer 24, the electron acceptor layer 25, and the common reflection electrode 16 from the outside side irradiated with sunlight Lc. It has a laminated structure arranged.

The common reflective electrode 16 includes the photoelectric conversion unit 10 and the photoelectric conversion unit 20 for taking out the current Ib generated by the photoelectric conversion unit 10 and the current Ic generated by the photoelectric conversion unit 20 to the outside (current storage unit 5). Common electrode.
The common reflective electrode 16 is a reflective electrode that reflects the white light Lb incident from the backlight unit 3 side and reflects the sunlight Lc incident from the outside.

The white light Lb is reflected by the common reflective electrode 16 through the electron donor layer 14, the electron acceptor layer 15 of the photoelectric conversion unit 10, and the charge separation region in the vicinity of the interface, and is again reflected by the electron donor layer 14 and the electrons. The light is irradiated toward the backlight unit 3 through the receptor layer 15 and the charge separation region in the vicinity of the interface.
That is, the white light Lb passes through the electron donor layer 14 and the electron acceptor layer 15 of the photoelectric conversion unit 10 and the charge separation region in the vicinity of the interface twice, so that the photoelectric conversion efficiency of the photoelectric conversion unit 10 is improved. To do.
Further, since the remaining white light Lb that has not been subjected to photoelectric conversion by the photoelectric conversion unit 10 enters the backlight unit 3, the irradiation efficiency of the backlight unit 3 to the liquid crystal display panel 2 is improved.

The sunlight Lc is reflected by the common reflecting electrode 16 through the electron donor layer 24, the electron acceptor layer 25 of the photoelectric conversion unit 20, and the charge separation region in the vicinity of the interface, and is again reflected by the electron donor layer 24, the electrons. It is discharged to the outside through the receptor layer 25 and the charge separation region in the vicinity of these interfaces.
That is, the sunlight Lc passes through the electron donor layer 24, the electron acceptor layer 25 of the photoelectric conversion unit 20 and the charge separation region near the interface thereof twice, so that the photoelectric conversion efficiency of the photoelectric conversion unit 20 is improved. To do.

  As an electron donor constituting the electron donor layers 14 and 24, at least a part overlaps the emission wavelength region of the white light Lb irradiated from the backlight unit 3 and the emission wavelength region of sunlight Lc irradiated from the outside. A dye having an absorption wavelength region (fluorescent dye) is used. In Example 1 (the same applies to Examples 2 to 6 described later), zinc phthalocyanine (ZnPc) was used as the electron donor constituting the electron donor layers 14 and 24.

  As the electron acceptor constituting the electron acceptor layers 15 and 25, at least a part of the emission wavelength region of the white light Lb irradiated from the backlight unit 3 and the emission wavelength region of sunlight Lc irradiated from the outside overlap. A dye having an absorption wavelength region (fluorescent dye) is used. In Example 1 (the same applies to Examples 2 to 6 described later), fullerene (C60) was used as the electron acceptor constituting the electron donor layers 14 and 24.

Here, the absorption spectra of fullerene and zinc phthalocyanine will be described with reference to FIGS.
FIG. 6 shows a typical example of the absorption spectrum of fullerene. FIG. 7 shows a representative example of the absorption spectrum of zinc phthalocyanine. 6 and 7, the horizontal axis indicates the absorption wavelength, and the vertical axis indicates the absorption intensity.

As shown in FIG. 6, the absorption spectrum of fullerene has a broad peak with a strong absorption intensity and a wide half-value width in the vicinity of the absorption wavelength of 540 nm.
On the other hand, as shown in FIG. 7, the absorption spectrum of zinc phthalocyanine has a peak with a strong absorption intensity near the absorption wavelength of 670 nm and a narrower half-value width than fullerene.

  Here, when the absorption spectrum of fullerene shown in FIG. 6 and the emission spectrum of LED shown in FIG. 3 described above are compared, the absorption peak of fullerene and the region in the vicinity thereof exist in the emission peak of LED and the region in the vicinity thereof. When the LED is used as the light source of the backlight unit 3, the white light Lb irradiated from the LED to the photoelectric conversion unit 10 can be efficiently absorbed by the electron acceptor layer 15.

  Next, comparing the absorption spectrum of zinc phthalocyanine shown in FIG. 7 with the emission spectrum of the LED shown in FIG. 3 described above, zinc phthalocyanine hardly absorbs light having a wavelength shorter than 550 nm. Therefore, when an LED is used as the light source of the backlight unit 3, the red light component having a wavelength of 550 nm or more in the white light Lb irradiated to the photoelectric conversion unit 10 is absorbed, whereas the green light component having a wavelength shorter than 550 nm is absorbed. And blue light components are hardly absorbed.

  Therefore, in the photoelectric conversion unit 10, when zinc phthalocyanine is used for the electron donor layer 14 and fullerene is used for the electron acceptor layer 15, mainly only the red light component of the white light Lb is photoelectrically converted by the photoelectric conversion unit 10. , Current Ib is generated.

  Similarly, in the photoelectric conversion unit 20, when zinc phthalocyanine is used for the electron donor layer 24 and fullerene is used for the electron acceptor layer 25, mainly the red light component of sunlight Lc is photoelectrically converted by the photoelectric conversion unit 20. Current Ic is generated.

  Even when an organic EL element is used as the light source of the backlight unit 3, only the red light component of the white light Lb is mainly photoelectrically converted by the photoelectric conversion unit 10 to generate a current Ib as in the case of using the LED described above. Is done. Moreover, mainly the red light component of sunlight Lc is photoelectrically converted by the photoelectric conversion unit 20 to generate a current Ic.

  An example of a method for manufacturing a light source of the backlight unit 3, for example, an organic EL element will be described below.

  A SiNO film is formed on a film-like polycarbonate (PC) substrate having a thickness of 125 μm by using a CVD (Chemical Vapor Deposition) method, and an ITO (Indium Tin Oxide) film as a transparent electrode is further formed on the SiNO film. The film is formed by a reactive ion beam sputtering method so that the film thickness is 150 nm and the sheet resistance is 20 Ω / square (ohm / square).

Next, a copper phthalocyanine (CuPc) film having a thickness of 60 nm, a vanadium pentoxide film having a thickness of 5 nm, and N, N′-di (1-naphthyl) -N, N′-diphenyl having a thickness of 20 nm are formed on the ITO film. Benzidine (NPD) film, 5 nm thick yellow light emitting layer, 30 nm thick blue light emitting layer, 6 nm thick tris- (8-hydroxyquinoline) aluminum (Alq ₃ ) film, and 10 nm thick 2,9- A dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) film is sequentially formed using a vacuum deposition method.

  Further, an Al film having a thickness of 5 nm is formed on the BCP film by using a vacuum deposition method, and then an ITO film having a thickness of 100 nm is formed on the Al film by using a reactive ion beam sputtering method.

  Thereafter, the finally formed ITO film is sealed with a sealing resin film having a laminated film of a UV curable resin and a SiNO film, thereby producing an organic EL element serving as a light source of the backlight unit 3. be able to.

  Next, an example of a method for manufacturing the photoelectric conversion unit 4 will be described below.

  A SiNO film is formed on a film-like polycarbonate substrate (transparent substrate 21) having a thickness of 125 μm by a CVD method, and an ITO film as a transparent electrode 22 is further formed on the SiNO film with a film thickness of 150 nm and a sheet resistance. The film is formed using a reactive ion beam sputtering method so that the current becomes 20Ω / □.

  Next, after the ITO film is partially etched and patterned, a coating solution for forming a hole extraction layer (conductive polymer paste; poly (3,4)) is formed on the polycarbonate substrate so as to cover the ITO film. -Ethylenedioxythiophene: aqueous dispersion of polystyrene sulfonic acid polymer) (PEDOT: PSS) is applied by spin coating and dried to form a hole extraction layer 23 having a thickness of 100 nm.

  Next, on the hole extraction layer 23, a zinc phthalocyanine (ZnPc) film having a thickness of 10 nm, which is an electron donor layer 24, zinc phthalocyanine and fullerene (C60) having a thickness of 15 nm and a molecular ratio of 1: 1. And a fullerene film having a thickness of 30 nm, which is the electron acceptor layer 25, are sequentially formed using a vacuum deposition method.

  Further, a 100 nm thick metal film, for example, an Al film, which is the common reflective electrode 16, is formed on the fullerene film by using a vacuum evaporation method to form the photoelectric conversion unit 20.

  Further, on the metal film (common reflective electrode 16), a fullerene film having a thickness of 30 nm as the electron acceptor layer 15, a mixed film of zinc phthalocyanine and fullerene having a thickness of 15 nm and a molecular ratio of 1: 1, and A 10-nm-thick zinc phthalocyanine film, which is the electron donor layer 14, is sequentially formed using a vacuum deposition method.

  Next, on the zinc phthalocyanine film (electron donor layer 14), the same coating solution for forming a hole extraction layer as described above is applied by spin coating and dried, and the hole extraction layer 13 having a thickness of 100 nm is dried. Form.

  Next, an ITO film as the transparent electrode 12 is formed on the hole extraction layer 13 by a reactive ion beam sputtering method so that the film thickness is 150 nm and the sheet resistance is 20 Ω / □.

  Furthermore, the ITO film formed last is sealed with a sealing resin film (sealing layer 11) having a laminated film of a UV curable resin and a SiNO film, whereby photoelectric conversion is performed on the photoelectric conversion unit 20. The photoelectric conversion unit 4 in which the unit 10 is stacked can be manufactured.

  According to the display device 1 described above, the white light Lb (mainly red light component) irradiated from the backlight unit 3 is photoelectrically converted by the photoelectric conversion unit 10 to generate the current Ib, and the sunlight Lc irradiated from the outside. In order to irradiate the liquid crystal display panel 2 with the white light La by photoelectrically converting (mainly the red light component) by the photoelectric conversion unit 20 to generate the current Ic and storing the currents Ib and Ic in the current storage unit 5. The current consumed in the current storage unit 5 can be supplemented with the generated currents Ib and Ic.

<Example 2>
Example 2 is different from Example 1 in that the electron donor layer includes a mixed film of zinc phthalocyanine and rubrene as a structure and a manufacturing method, and the other structure and manufacturing method are different from those of Example 1. The same.
Therefore, the following description will be made with reference to FIGS. 8 and 9 with a focus on components and manufacturing methods different from those of the first embodiment. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals for easy understanding.

  As shown in FIG. 8, the display device 30 of Example 2 includes a transmissive liquid crystal display panel 2 having a display surface A2 and a back surface B2 facing each other, and a light emitting surface A3 and a light emitting surface B3 facing each other. For example, white light La is emitted from the light emitting surface A3 toward the back surface B2 of the liquid crystal display panel 2, and, for example, white light Lb is emitted from the light emitting surface B3 toward the light receiving surface A4 of the photoelectric conversion unit 34 described later. The light receiving surface A4 that receives the white light Lb emitted from the backlight unit 3 and the light emitting surface B3 of the double-sided backlight unit 3, and the light receiving surface that receives external light emitted from the outside, for example, sunlight Lc. B4, a photoelectric conversion unit that photoelectrically converts white light Lb received by the light receiving surface A4 to generate a current Id, and photoelectrically converts sunlight Lc received by the light receiving surface B4 to generate a current Ie. 34, a current reservoir 5 such as a battery for storing current Id and the current Ie generated by the photoelectric conversion unit 34, and a.

  As shown in FIG. 9, the photoelectric conversion unit 34 photoelectrically converts the white light Lb irradiated from the light emitting surface B3 (see FIG. 8) of the backlight unit 3 to the light receiving surface A4 to generate a current Id. 35 and a photoelectric conversion unit 36 that photoelectrically converts sunlight Lc irradiated on the light receiving surface B4 from the outside to generate a current Ie.

  The photoelectric conversion unit 35 is arranged in the order of the sealing layer 11, the transparent electrode 12, the hole extraction layer 13, the electron donor layer 37, the electron acceptor layer 15, and the common reflective electrode 16 from the backlight unit 3 side. It has a laminated structure.

  The photoelectric conversion unit 36 is arranged in the order of the transparent substrate 21, the transparent electrode 22, the hole extraction layer 23, the electron donor layer 38, the electron acceptor layer 25, and the common reflective electrode 16 from the outside irradiated with sunlight Lc. It has a laminated structure arranged.

  Next, an example of a method for manufacturing the photoelectric conversion unit 34 will be described below.

  Similarly to Example 1, a SiNO film was formed on a film-like polycarbonate substrate (transparent substrate 21) having a thickness of 125 μm by using the CVD method, and an ITO film as the transparent electrode 22 was further formed on the SiNO film. The film is formed by a reactive ion beam sputtering method so that the film thickness is 150 nm and the sheet resistance is 20 Ω / □.

  Next, in the same manner as in Example 1, after the ITO film was partially etched and patterned, a hole extraction layer forming coating solution (PEDOT: PSS) was applied onto the polycarbonate substrate so as to cover the ITO film. A hole extraction layer 23 having a thickness of 100 nm is formed by applying and drying by spin coating.

  Next, on the hole extraction layer 23, a zinc phthalocyanine film having a thickness of 10 nm, a mixed film of zinc phthalocyanine and rubrene having a thickness of 10 nm and a molecular ratio of 1: 0.05, and a zinc phthalocyanine having a thickness of 5 nm are formed. The films are sequentially formed using a vacuum evaporation method, and the electron donor layer 38 is formed.

  Further, on the zinc phthalocyanine film formed last, a mixed film of zinc phthalocyanine and fullerene having a thickness of 15 nm and a molecular ratio of 1: 1, and a fullerene film having a thickness of 30 nm as the electron acceptor layer 25 are formed. The films are sequentially formed using a vacuum deposition method.

  Thereafter, a 100 nm-thick metal film, for example, an Al film, which is the common reflective electrode 16, is sequentially formed on the fullerene film by using a vacuum evaporation method to form the photoelectric conversion unit 36.

Further, on the metal film (common reflective electrode 16), a fullerene film having a thickness of 30 nm as the electron acceptor layer 15, a mixed film of zinc phthalocyanine and fullerene having a thickness of 15 nm and a molecular ratio of 1: 1, A zinc phthalocyanine film having a thickness of 5 nm, a mixed film of zinc phthalocyanine and rubrene having a thickness of 10 nm and a molecular ratio of 1: 0.05, and a zinc phthalocyanine film having a thickness of 10 nm are sequentially formed using a vacuum deposition method. To do.
Finally, the zinc phthalocyanine film, the mixed film of zinc phthalocyanine and rubrene, and the zinc phthalocyanine film formed as the electron donor layer 37 are formed.

  Next, in the same manner as in Example 1, the same coating liquid for forming a hole extraction layer (PEDOT: PSS) as described above was spin-coated onto the zinc phthalocyanine film (electron donor layer 37) formed last. And dried to form a hole extraction layer 13 having a thickness of 100 nm.

  Next, an ITO film as the transparent electrode 12 is formed on the hole extraction layer 13 by a reactive ion beam sputtering method so that the film thickness is 150 nm and the sheet resistance is 20 Ω / □.

  Furthermore, the last ITO film formed is sealed with a sealing resin film (sealing layer 11) having a laminated film of a UV curable resin and a SiNO film, whereby photoelectric conversion is performed on the photoelectric conversion portion 36. The photoelectric conversion unit 34 in which the portions 35 are stacked can be manufactured.

Here, the absorption spectrum and emission spectrum of rubrene will be described with reference to FIG.
FIG. 10 shows representative examples of the absorption spectrum and emission spectrum of rubrene. In FIG. 10, the horizontal axis indicates the absorption wavelength and the emission wavelength, and the vertical axis indicates the absorption intensity and the emission intensity.

  As shown in FIG. 10, the absorption spectrum of rubrene has strong absorption peaks near 490 nm and 520 nm, and some of them overlap each other, so that light in the range of about 450 nm to 550 nm is obtained. That is, the green component light can be efficiently absorbed.

  On the other hand, as shown in FIG. 10, the emission spectrum of rubrene has a peak with a strong emission intensity near the emission wavelength of 550 nm.

  Here, when the emission spectrum of rubrene shown in FIG. 10 is compared with the absorption spectrum of zinc phthalocyanine shown in FIG. 7, the emission peak of rubrene and the vicinity thereof overlap with the absorption peak of zinc phthalocyanine and the vicinity thereof. Since the region exists, the energy of the green light component absorbed by rubrene can be transferred to zinc phthalocyanine.

  Therefore, in the photoelectric conversion unit 35, when a mixed film of zinc phthalocyanine and rubrene is used for the electron donor layer 37 and fullerene is used for the electron acceptor layer 15, the green color is mainly added to the red light component of the white light Lb. The light component is also photoelectrically converted by the photoelectric conversion unit 35 to generate a current Id.

  Similarly, in the photoelectric conversion unit 36, when a mixed film of zinc phthalocyanine and rubrene is used for the electron donor layer 38 and fullerene is used for the electron acceptor layer 25, mainly in addition to the red light component of the sunlight Lc. The green light component is also photoelectrically converted by the photoelectric conversion unit 36, and a current Ie is generated.

  According to the display device 30 described above, the white light Lb (mainly red component and green component) irradiated from the backlight unit 3 is photoelectrically converted by the photoelectric conversion unit 35 to generate the current Id, and the sun irradiated from the outside Light Lc (mainly red component and green component) is photoelectrically converted by the photoelectric conversion unit 36 to generate a current Ie, and the currents Id and Ie are stored in the current storage unit 5, whereby white light La is supplied to the liquid crystal display panel 2. The current consumed in the current storage unit 5 for irradiation can be supplemented with the generated currents Id and Ie.

  In the display device 1 of the first embodiment described above, the white light Lb and the red light component of the sunlight Lc are mainly photoelectrically converted to generate the currents Ib and Ic, whereas in the display device 30 of the second embodiment, the current is generated. In addition to the red light component of the white light Lb and the sunlight Lc, the green light component is also photoelectrically converted to generate currents Id and Ie, so that the photoelectric conversion efficiency is further improved as compared with the display device 1 of the first embodiment. The production amount of can be increased.

<Example 3>
Example 3 is different from Examples 1 and 2 in that the electron donor layer includes a mixed film of zinc phthalocyanine, rubrene, and coumarin and a manufacturing method, and other configurations and manufacturing methods are as follows. The same as in Examples 1 and 2.
Therefore, the following description will be made with reference to FIGS. 11 and 12 with a focus on components and manufacturing methods different from those in the first and second embodiments. In the third embodiment, the same components as those in the first and second embodiments are denoted by the same reference numerals for easy understanding.

  As shown in FIG. 11, the display device 40 of Example 3 has a transmissive liquid crystal display panel 2 having a display surface A2 and a back surface B2 facing each other, and a light emitting surface A3 and a light emitting surface B3 facing each other. For example, white light La is emitted from the light emitting surface A3 toward the back surface B2 of the liquid crystal display panel 2, and, for example, white light Lb is emitted from the light emitting surface B3 toward the light receiving surface A4 of the photoelectric conversion unit 44 described later. The light receiving surface A4 that receives the white light Lb emitted from the backlight unit 3 and the light emitting surface B3 of the double-sided backlight unit 3, and the light receiving surface that receives external light emitted from the outside, for example, sunlight Lc. B4, a photoelectric conversion unit that photoelectrically converts white light Lb received by the light receiving surface A4 to generate a current If, and photoelectrically converts sunlight Lc received by the light receiving surface B4 to generate a current Ig. And bets 44, a current reservoir 5 such as a battery for storing current If and the current Ig generated by the photoelectric conversion unit 44, and a.

  As shown in FIG. 12, the photoelectric conversion unit 44 photoelectrically converts the white light Lb irradiated from the light emitting surface B3 (see FIG. 11) of the backlight unit 3 to the light receiving surface A4 to generate a current If. 45 and a photoelectric conversion unit 46 that photoelectrically converts sunlight Lc irradiated on the light receiving surface B4 from the outside to generate a current Ig.

  The photoelectric conversion unit 45 is arranged in the order of the sealing layer 11, the transparent electrode 12, the hole extraction layer 13, the electron donor layer 47, the electron acceptor layer 15, and the common reflective electrode 16 from the backlight unit 3 side. It has a laminated structure.

  The photoelectric conversion unit 46 is arranged in the order of the transparent substrate 21, the transparent electrode 22, the hole extraction layer 23, the electron donor layer 48, the electron acceptor layer 25, and the common reflective electrode 16 from the outside irradiated with sunlight Lc. It has a laminated structure arranged.

  Next, an example of a method for manufacturing the photoelectric conversion unit 44 will be described below.

  As in Examples 1 and 2, a SiNO film was formed on a film-like polycarbonate substrate (transparent substrate 21) having a thickness of 125 μm by using the CVD method, and ITO which is the transparent electrode 22 was further formed on the SiNO film. The film is formed by a reactive ion beam sputtering method so that the film thickness is 150 nm and the sheet resistance is 20 Ω / □.

  Next, as in Examples 1 and 2, the ITO film was partially etched and patterned, and then a hole extraction layer forming coating solution (PEDOT: PSS) was formed on the polycarbonate substrate so as to cover the ITO film. ) Is applied by a spin coat method and dried to form a hole extraction layer 23 having a thickness of 100 nm.

  Next, on the hole extraction layer 23, a zinc phthalocyanine film having a thickness of 10 nm, a mixed film of zinc phthalocyanine, rubrene, and coumarin having a thickness of 10 nm and a molecular ratio of 1: 0.05: 0.05, and A zinc phthalocyanine film having a thickness of 5 nm is sequentially formed using a vacuum vapor deposition method to form an electron donor layer 48.

  Further, on the zinc phthalocyanine film formed last, a mixed film of zinc phthalocyanine and fullerene having a thickness of 15 nm and a molecular ratio of 1: 1, and a fullerene film having a thickness of 30 nm as the electron acceptor layer 25 are formed. The films are sequentially formed using a vacuum deposition method.

  Thereafter, a 100 nm-thick metal film, for example, an Al film, which is the common reflective electrode 16, is sequentially formed on the fullerene film by using a vacuum evaporation method, thereby forming the photoelectric conversion unit 46.

Further, on the metal film (common reflective electrode 16), a fullerene film having a thickness of 30 nm as the electron acceptor layer 15, a mixed film of zinc phthalocyanine and fullerene having a thickness of 15 nm and a molecular ratio of 1: 1, A vacuum deposition method using a zinc phthalocyanine film having a thickness of 5 nm, a mixed film of zinc phthalocyanine, rubrene and coumarin having a thickness of 10 nm and a molecular ratio of 1: 0.05: 0.05, and a zinc phthalocyanine film having a thickness of 10 nm. Are sequentially formed.
Finally, the zinc phthalocyanine film, the mixed film of zinc phthalocyanine, rubrene and coumarin, and the zinc phthalocyanine film formed as the electron donor layer 47 are formed.

  Next, as in Examples 1 and 2, the same hole extraction layer forming coating solution (PEDOT: PSS) as described above was spun onto the zinc phthalocyanine film (electron donor layer 47) formed last. A hole extraction layer 13 having a thickness of 100 nm is formed by applying and drying by a coating method.

  Next, an ITO film as the transparent electrode 12 is formed on the hole extraction layer 13 by a reactive ion beam sputtering method so that the film thickness is 150 nm and the sheet resistance is 20 Ω / □.

  Furthermore, the ITO film formed last is sealed with a sealing resin film (sealing layer 11) having a laminated film of a UV curable resin and a SiNO film, whereby photoelectric conversion is performed on the photoelectric conversion unit 46. The photoelectric conversion unit 44 in which the portion 45 is stacked can be manufactured.

Here, the absorption spectrum and emission spectrum of coumarin will be described with reference to FIG.
FIG. 13 shows representative examples of the absorption spectrum and emission spectrum of coumarin. In FIG. 13, the horizontal axis indicates the absorption wavelength and the emission wavelength, and the vertical axis indicates the absorption intensity and the emission intensity.

  As shown in FIG. 13, since the absorption spectrum of coumarin has a peak with a strong absorption intensity in the vicinity of 400 nm, coumarin can efficiently absorb blue component light.

  On the other hand, as shown in FIG. 13, the emission spectrum of coumarin has a strong emission intensity peak at an emission wavelength of around 390 nm.

Here, when the emission spectrum of coumarin shown in FIG. 13 is compared with the absorption spectrum of rubrene shown in FIG. 10 described above, the emission peak of coumarin and the vicinity thereof overlap with the absorption peak of rubrene and the vicinity thereof. Because it exists, the energy of the blue light component absorbed by the coumarin can be transferred to rubrene.
The energy of the blue light component that has moved to rubrene moves to zinc phthalocyanine for the same reason as described above.

  Therefore, in the photoelectric conversion unit 45, when a mixed film of zinc phthalocyanine, rubrene, and coumarin is used for the electron donor layer 47 and fullerene is used for the electron acceptor layer 15, the red light component and the green light of the white light Lb are mainly used. In addition to the light component, the blue light component is also photoelectrically converted by the photoelectric conversion unit 45 to generate a current If.

  Similarly, in the photoelectric conversion unit 46, when a mixed film of zinc phthalocyanine, rubrene, and coumarin is used for the electron donor layer 48 and fullerene is used for the electron acceptor layer 25, the red light component of the sunlight Lc and In addition to the green light component, the blue light component is also photoelectrically converted by the photoelectric conversion unit 46 to generate a current Ig.

  According to the display device 40 described above, the white light Lb (mainly the red component, the green component, and the blue component) emitted from the backlight unit 3 is photoelectrically converted by the photoelectric conversion unit 45 to generate the current If, and externally. The irradiated sunlight Lc (mainly red component, green component, and blue component) is photoelectrically converted by the photoelectric conversion unit 46 to generate a current Ig, and these currents If and Ig are stored in the current storage unit 5, thereby liquid crystal. The current consumed by the current storage unit 5 to irradiate the display panel 2 with the white light La can be supplemented with the generated currents If and Ig.

  Further, in the display device 1 of the first embodiment described above, the red light components of the white light Lb and the sunlight Lc are mainly photoelectrically converted to generate currents Ib and Ic, whereas in the display device 40 of the third embodiment, the current Ib and Ic are generated. In addition to the red light components of the white light Lb and the sunlight Lc, the green light component and the blue light component are also photoelectrically converted to generate the currents If and Ig, so that the photoelectric conversion efficiency is higher than that of the display device 1 of the first embodiment. And the amount of current generation can be increased.

  In the display device 30 of the second embodiment described above, the red light component and the green light component of the white light Lb and sunlight Lc are mainly photoelectrically converted to generate currents Id and Ie. In the display device 40, in addition to the red light component and the green light component of the white light Lb and the sunlight Lc, the blue light component is also photoelectrically converted to generate currents If and Ig. Photoelectric conversion efficiency is improved, and the amount of current generation can be increased.

<Example 4>
In the first embodiment, the photoelectric conversion unit 4 has the configuration and the manufacturing method having the two photoelectric conversion units 20 and 30, whereas in the fourth embodiment, the photoelectric conversion unit 54 has the configuration having the one photoelectric conversion unit 55 and It differs in the point which was set as the manufacturing method, and the other structure and manufacturing method are the same as Example 1. FIG.
Therefore, the following description will be made with reference to FIGS. 14 and 15 with a focus on components and manufacturing methods different from those of the first embodiment. In the fourth embodiment, the same components as those in the first to third embodiments are denoted by the same reference numerals for easy understanding.

  As shown in FIG. 14, the display device 50 of Example 4 has a transmissive liquid crystal display panel 2 having a display surface A2 and a back surface B2 facing each other, and a light emitting surface A3 and a light emitting surface B3 facing each other. For example, white light La is emitted from the light emitting surface A3 toward the back surface B2 of the liquid crystal display panel 2, and for example, white light Lb is emitted from the light emitting surface B3 toward the light receiving surface A54 of the photoelectric conversion unit 54 described later. The light receiving surface A54 that receives the white light Lb emitted from the backlight unit 3 and the light emitting surface B3 of the dual emission type backlight unit 3, and the light receiving surface that receives external light, for example, sunlight Lc, emitted from the outside. Light that has B54, photoelectrically converts white light Lb received by the light receiving surface A54 to generate current Ih, and photoelectrically converts sunlight Lc received by the light receiving surface B54 to generate current Ii A conversion unit 54, a current reservoir 5 such as a battery for storing current Ih and current Ii generated in the photoelectric conversion unit 54, and a.

  As shown in FIG. 15, the photoelectric conversion unit 54 photoelectrically converts the white light Lb irradiated from the light emitting surface B3 (see FIG. 14) of the backlight unit 3 to the light receiving surface A54 to generate a current Ih, and externally. The photoelectric conversion part 55 which photoelectrically converts sunlight Lc irradiated to the light-receiving surface B54 and produces | generates the electric current Ii is provided.

  The photoelectric conversion unit 55 includes, from the backlight unit 3 side, a sealing layer 11, a semi-transmissive / semi-reflective electrode 52, an electron acceptor layer 15 (25), an electron donor layer 14 (24), and a hole extraction layer 13 (23 ), A transparent electrode 22 and a transparent substrate 21 in this order.

  The semi-transmissive / semi-reflective electrode 52 transmits a part of the white light Lb incident from the backlight unit 3 side and reflects the rest as compared with the common reflective electrode 16 and the transparent electrode 12 of the first embodiment. In addition, a part of sunlight Lc incident from the outside is transmitted and the rest is reflected.

Part of the white light Lb is transmitted through the semi-transmissive and semi-reflective electrode 52 of the photoelectric conversion unit 55, and charge separation in the vicinity of the electron acceptor layer 15 (25), the electron donor layer 14 (24), and the interface between them. While reaching the region, the remainder of the white light Lb is reflected by the semi-transmissive / semi-reflective electrode 52 and irradiated toward the backlight unit 3.
That is, a part of the white light Lb is photoelectrically converted by the photoelectric conversion unit 55 to generate a current Ih, and the rest is reflected toward the backlight unit 3, so that the liquid crystal display panel 2 of the backlight unit 3 is reflected. Irradiation efficiency is improved.

The sunlight Lc reaches the transflective electrode 52 through the electron donor layer 14 (24), the electron acceptor layer 15 (25) of the photoelectric conversion unit 55, and the charge separation region in the vicinity of the interface, A part of the light is reflected by the semi-transmissive and semi-reflective electrode 52 and is emitted to the outside again through the electron acceptor layer 15 (25), the electron donor layer 14 (24), and the charge separation region in the vicinity of these interfaces.
That is, since sunlight Lc passes twice through the electron donor layer 14 (24), the electron acceptor layer 15 (25) of the photoelectric conversion unit 55, and the charge separation region in the vicinity of the interface, the photoelectric conversion unit 55 The photoelectric conversion efficiency is improved.

  Next, an example of a method for manufacturing the photoelectric conversion unit 54 will be described below.

  Similarly to Example 1, a SiNO film was formed on a film-like polycarbonate substrate (transparent substrate 21) having a thickness of 125 μm by using the CVD method, and an ITO film as the transparent electrode 22 was further formed on the SiNO film. The film is formed by a reactive ion beam sputtering method so that the film thickness is 150 nm and the sheet resistance is 20 Ω / □.

  Next, in the same manner as in Example 1, after the ITO film was partially etched and patterned, the hole extraction layer forming coating solution (PEDOT: PSS) was formed on the polycarbonate substrate so as to cover the ITO film. ) Is applied by spin coating and dried to form a hole extraction layer 13 (23) having a thickness of 100 nm.

  Next, on the hole extraction layer 13 (23), a zinc phthalocyanine (ZnPc) film having a thickness of 10 nm, which is an electron donor layer 14 (24), and a zinc phthalocyanine having a thickness of 15 nm and a molecular ratio of 1: 1 And a fullerene film having a thickness of 30 nm, which is the electron acceptor layer 15 (25), are sequentially formed using a vacuum deposition method.

  Further, an ITO film and an Al film are respectively formed on the fullerene film with a predetermined thickness to form a transflective electrode 52.

  Furthermore, the photoelectric conversion unit 54 can be produced by sealing the transflective electrode 52 with a sealing resin film (sealing layer 11) having a laminated film of a UV curable resin and a SiNO film. it can.

  According to the display device 50 described above, the white light Lb (mainly red light component) emitted from the backlight unit 3 is photoelectrically converted by the photoelectric conversion unit 54 for the same reason as described in the first embodiment. The current Ih is generated, the sunlight Lc (mainly red light component) irradiated from the outside is photoelectrically converted by the photoelectric conversion unit 54 to generate the current Ii, and the currents Ih and Ii are stored in the current storage unit 5. Thus, the current consumed by the current storage unit 5 for irradiating the liquid crystal display panel 2 with the white light La can be supplemented with the generated currents Ih and Ii.

<Example 5>
Example 5 is different from Example 4 in that the electron donor layer includes a mixed film of zinc phthalocyanine and rubrene as the electron donor layer and a manufacturing method. Other configurations and manufacturing methods are different from those of Example 4. The same.
That is, the relationship between Example 5 and Example 4 is the same as the relationship between Example 2 and Example 1 described above.
In the fifth embodiment, the same components as those in the first to fourth embodiments are denoted by the same reference numerals for easy understanding.

  As shown in FIG. 16, the display device 60 of Example 5 has a transmissive liquid crystal display panel 2 having a display surface A2 and a back surface B2 facing each other, and a light emitting surface A3 and a light emitting surface B3 facing each other. For example, white light La is emitted from the light emitting surface A3 toward the back surface B2 of the liquid crystal display panel 2, and, for example, white light Lb is emitted from the light emitting surface B3 toward the light receiving surface A54 of the photoelectric conversion unit 64 described later. The light receiving surface A54 that receives the white light Lb emitted from the backlight unit 3 and the light emitting surface B3 of the dual emission type backlight unit 3, and the light receiving surface that receives external light, for example, sunlight Lc, emitted from the outside. Light that has B54, photoelectrically converts white light Lb received by the light receiving surface A54 to generate current Ij, and photoelectrically converts sunlight Lc received by the light receiving surface B54 to generate current Ik. A conversion unit 64, a current reservoir 5 such as a battery for storing current Ij and the current Ik generated by the photoelectric conversion unit 64, and a.

  As shown in FIG. 17, the photoelectric conversion unit 64 photoelectrically converts the white light Lb irradiated from the light emitting surface B3 (see FIG. 16) of the backlight unit 3 to the light receiving surface A54 to generate a current Ij, and externally. The photoelectric conversion part 65 which photoelectrically converts sunlight Lc irradiated to the light-receiving surface B54 and produces | generates the electric current Ik is provided.

  The photoelectric conversion unit 65 includes, from the backlight unit 3 side, a sealing layer 11, a semi-transmissive / semi-reflective electrode 52, an electron acceptor layer 15 (25), an electron donor layer 37 (38), and a hole extraction layer 13 (23 ), A transparent electrode 22 and a transparent substrate 21 in this order.

  According to the display device 60 described above, the white light Lb (mainly the red light component and the green light component) emitted from the backlight unit 3 is photoelectrically converted by the photoelectric conversion unit 65 to generate the current Ij, which is irradiated from the outside. The sunlight Lc (mainly the red light component and the green light component) is photoelectrically converted by the photoelectric conversion unit 65 to generate a current Ik, and the currents Ij and Ik are stored in the current storage unit 5, whereby the liquid crystal display panel 2 is obtained. The current consumed by the current storage unit 5 for irradiating the white light La can be supplemented by the generated currents Ij and Ik.

  In the display device 50 of the fourth embodiment described above, the white light Lb and the red light component of the sunlight Lc are mainly photoelectrically converted to generate currents Ih and Ii, whereas in the display device 60 of the fifth embodiment, the current Ih and Ii are generated. In addition to the red light component of the white light Lb and the sunlight Lc, the green light component is also photoelectrically converted to generate currents Ij and Ik, so that the photoelectric conversion efficiency is further improved compared to the display device 50 of Example 4, and the current The production amount of can be increased.

<Example 6>
Example 6 is different from Examples 4 and 5 in that the electron donor layer includes a mixed film of zinc phthalocyanine, rubrene, and coumarin and a manufacturing method, and other configurations and manufacturing methods are as follows. The same as in Examples 4 and 5.
That is, the relationship between the sixth embodiment and the fourth and fifth embodiments is the same as the relationship between the third embodiment and the first and second embodiments.
In the sixth embodiment, the same components as those in the first to fifth embodiments are denoted by the same reference numerals for easy understanding.

  As shown in FIG. 18, the display device 70 of Example 6 has a transmissive liquid crystal display panel 2 having a display surface A2 and a back surface B2 facing each other, and a light emitting surface A3 and a light emitting surface B3 facing each other. For example, white light La is emitted from the light emitting surface A3 toward the back surface B2 of the liquid crystal display panel 2, and for example, white light Lb is emitted from the light emitting surface B3 toward the light receiving surface A54 of the photoelectric conversion unit 74 described later. The light receiving surface A54 that receives the white light Lb emitted from the backlight unit 3 and the light emitting surface B3 of the dual emission type backlight unit 3, and the light receiving surface that receives external light, for example, sunlight Lc, emitted from the outside. B54, light that photoelectrically converts white light Lb received by the light receiving surface A54 to generate current Im, and photoelectrically converts sunlight Lc received by the light receiving surface B54 to generate current In A conversion unit 74, a current reservoir 5 such as a battery for storing current Im and a current In which is generated by the photoelectric conversion unit 74, and a.

  As shown in FIG. 19, the photoelectric conversion unit 74 photoelectrically converts the white light Lb irradiated from the light emitting surface B3 (see FIG. 18) of the backlight unit 3 to the light receiving surface A54 to generate a current Im, and externally. The photoelectric conversion part 75 which photoelectrically converts sunlight Lc irradiated to the light-receiving surface B54 and produces | generates electric current In is provided.

  The photoelectric conversion unit 75 includes, from the backlight unit 3 side, the sealing layer 11, the transflective electrode 52, the electron acceptor layer 15 (25), the electron donor layer 47 (48), and the hole extraction layer 13 (23 ), A transparent electrode 22 and a transparent substrate 21 in this order.

  According to the display device 70 described above, the white light Lb (mainly the red light component, the green light component, and the blue light component) irradiated from the backlight unit 3 is photoelectrically converted by the photoelectric conversion unit 75 to generate the current Im. The sunlight Lc (mainly red light component, green light component, and blue light component) irradiated from the outside is photoelectrically converted by the photoelectric conversion unit 46 to generate a current In, and these currents Im and In are converted into the current storage unit 5. The current consumed by the current storage unit 5 for irradiating the liquid crystal display panel 2 with the white light La can be supplemented by the generated currents Im and In.

  Further, in the display device 50 of the fourth embodiment described above, the red light components of the white light Lb and the sunlight Lc are mainly photoelectrically converted to generate currents Ih and Ii, whereas in the display device 70 of the sixth embodiment, the current Ih and Ii are generated. In addition to the red light components of the white light Lb and the sunlight Lc, the green light component and the blue light component are also photoelectrically converted to generate the currents Im and In, so that the photoelectric conversion efficiency is higher than that of the display device 50 of the fourth embodiment. And the amount of current generation can be increased.

  In the display device 60 of the fifth embodiment described above, the red light component and the green light component of the white light Lb and the sunlight Lc are mainly photoelectrically converted to generate currents Ij and Ik. In the display device 70, in addition to the red light component and the green light component of the white light Lb and sunlight Lc, the blue light component is also photoelectrically converted to generate currents Im and In. Photoelectric conversion efficiency is improved, and the amount of current generation can be increased.

  The embodiment of the present invention is not limited to the configuration and procedure described above, and it goes without saying that modifications may be made without departing from the scope of the present invention.

  For example, in Examples 1 to 3, the configuration of the photoelectric conversion unit (photoelectric conversion unit) is configured such that the backlight side is a sealing layer and the side irradiated with external light such as sunlight is a transparent substrate. It is not limited. For example, contrary to the above configuration, the backlight side may be a transparent substrate, and the side irradiated with external light such as sunlight may be a sealing layer.

In Examples 4 to 6, the configuration of the photoelectric conversion unit (photoelectric conversion unit) is such that the backlight side is a sealing layer and the side irradiated with external light such as sunlight is a transparent substrate. It is not limited. For example, contrary to the above configuration, the backlight side may be a transparent substrate, and the side irradiated with external light such as sunlight may be a sealing layer.
However, since the light intensity emitted from the outside, such as sunlight, is usually stronger than the light emitted from the backlight with respect to the photoelectric conversion unit (photoelectric conversion unit), sunlight is the electron donor layer. , The electron acceptor layer, and the charge separation region in the vicinity of these interfaces are preferably used in the same configuration as in Examples 4-6.

  Moreover, in Examples 1-6, although zinc phthalocyanine (ZnPc) was used as a material of an electron donor layer, it is not limited to this, For example, it replaces with zinc phthalocyanine (ZnPc) and uses copper phthalocyanine (CuPc). It may be used.

  In Examples 2 and 3, the two electron donor layers (37, 38) and (47, 48) each include rubrene. However, the present invention is not limited to this. For example, one of the electron donor layers is provided. Only the body layer may include rubrene.

  In Example 3, the two electron donor layers 47 and 48 each include a coumarin. However, the present invention is not limited to this. For example, only one electron donor layer may include a coumarin. Good.

1, 30, 40, 50, 60, 70_display device, 2_liquid crystal display panel, 3_backlight unit, 4,34,44,54,64,74_photoelectric conversion unit, 5_current storage unit, 10, 20, 35, 36, 45, 46, 55, 65, 75_photoelectric conversion part, 11_sealing layer, 12,22_transparent electrode, 13,23_hole extraction layer, 14, 24, 37, 38, 47, 48_electron donor layer, 15, 25_ electron acceptor layer, 16_ common reflective electrode, 21_ transparent substrate, 52_ transflective electrode, A2_ display surface, A3_ light emitting surface, A4, A54_ light receiving surface, B2_ back surface, B3_ light emitting surface, B4, B54_ light receiving surface , La, Lb_white light, Lc_sunlight, Ib to In_current

Claims (7)

A display panel having an image display surface and a back surface facing the display surface;
A backlight unit that irradiates the first light toward the back surface of the display panel and irradiates the second light in a direction different from the back surface;
A first light receiving surface that receives the second light and a second light receiving surface that receives the third light from the outside, and photoelectrically converts the second light received by the first light receiving surface. A photoelectric conversion unit that generates a first current and photoelectrically converts the third light received by the second light receiving surface to generate a second current;
A display device comprising: The photoelectric conversion unit is
A transparent substrate having either one of the first light receiving surface and the second light receiving surface, and a first facing surface facing the one light receiving surface;
Sequentially formed on the first facing surface of the transparent substrate;
A first transparent electrode;
A first hole extraction layer;
A first electron donor layer;
A first electron acceptor layer;
A common reflective electrode that reflects the second light and the third light;
A second electron acceptor layer;
A second electron donor layer;
A second hole extraction layer;
A second transparent electrode;
A sealing layer;
The display device according to claim 1, further comprising:   The first electron donor layer, the second electron donor layer, the first electron acceptor layer, and the second electron acceptor layer include a wavelength region of the second light and the third electron acceptor layer. The display device according to claim 2, further comprising a first dye having an absorption wavelength region that at least partially overlaps the wavelength region of the light.   The first electron donor layer, the second electron donor layer, the first electron acceptor layer, or the second electron acceptor layer includes a wavelength region of the second light and the third electron acceptor layer. And a second dye having an emission wavelength region that at least partially overlaps the absorption wavelength region of the first dye. 4. The display device according to claim 3, wherein The photoelectric conversion unit is
A transparent substrate having either one of the first light receiving surface and the second light receiving surface, and a first facing surface facing the one light receiving surface;
Sequentially formed on the first facing surface of the transparent substrate;
A transparent electrode;
A hole extraction layer;
An electron donor layer;
An electron acceptor layer;
A transflective electrode that transmits part of the second light and part of the third light, and reflects the rest of the light, respectively.
A sealing layer;
The display device according to claim 1, further comprising:   The electron donor layer and the electron acceptor layer each include a third dye having an absorption wavelength region that at least partially overlaps the wavelength region of the second light and the wavelength region of the third light, respectively. The display device according to claim 5, wherein:   The electron donor layer or the electron acceptor layer has an absorption wavelength region that at least partially overlaps the wavelength region of the second light and the wavelength region of the third light, respectively, The display device according to claim 6, further comprising a fourth dye having a light emission wavelength region at least partially overlapping the absorption wavelength region.

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